Copolymer, piezoelectric material, piezoelectric film, and piezoelectric element

Abstract

A copolymer has a structural unit represented by (1) (R is any one selected from a hydrogen atom, a methyl group, an ethyl group, a methoxymethyl group, a propyl group, an isopropyl group, a cyclopropyl group, a butyl group, an isobutyl group, a (trimethyl)methyl group, a pentyl group, an isopentyl group, a t-pentyl group, a neopentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, an adamantyl group, a phenyl group optionally having a substituent, an o-, m- or p-acetamidophenyl group, an o-, m- or p-benzamide group, an o-, m- or p-(methyl)benzamide group, an o-, m- or p-(N,N-dimethyl)benzamide group, a benzyl group optionally having a substituent and a phenoxymethyl group) and a structural unit represented by (2).

1 . A copolymer having a structural unit represented by the following general formula (1) and a structural unit represented by the following formula (2), 
       
         
           
           
               
               
           
         
         (in the general formula (1), R is any one selected from a hydrogen atom, a methyl group, an ethyl group, a methoxymethyl group, a propyl group, an isopropyl group, a cyclopropyl group, a butyl group, an isobutyl group, a (trimethyl)methyl group, a pentyl group, an isopentyl group, a t-pentyl group, a neopentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, an adamantyl group, a phenyl group optionally having one to five substituents selected from a methyl group, an ethyl group, a methoxy group, an ethoxy group, a fluoro group, a trifluoromethyl group and a cyano group at any positions, an o-acetamidophenyl group, a m-acetamidophenyl group, a p-acetamidophenyl group, an o-benzamide group, a m-benzamide group, a p-benzamide group, an o-(methyl)benzamide group, a m-(methyl)benzamide group, a p-(methyl)benzamide group, an o-(N,N-dimethyl)benzamide group, a m-(N,N-dimethyl)benzamide group, a p-(N,N-dimethyl)benzamide group, a benzyl group optionally having one to five substituents selected from a methyl group, an ethyl group, a methoxy group, an ethoxy group, a fluoro group, a trifluoromethyl group and a cyano group at any positions and a phenoxymethyl group). 
       
     
     
         2 . The copolymer according to  claim 1 ,
 wherein, in the general formula (1), R is any one of a hydrogen atom, a methyl group, a butyl group, a phenyl group and a cyanophenyl group.   
     
     
         3 . The copolymer according to  claim 1 ,
 wherein a content of the structural unit represented by the formula (2) is 20 to 80 mol %.   
     
     
         4 . A piezoelectric material comprising:
 the copolymer according to  claim 1 .   
     
     
         5 . A piezoelectric film comprising:
 the copolymer according to  claim 1 .   
     
     
         6 . A piezoelectric element comprising:
 the piezoelectric film according to claim  5 ; and   an electrode disposed on a surface of the piezoelectric film.